I just downloaded and tested your FireMonkey TMS Component Pack including TMSFMXToolBarButton. I'm searching for a colored button and I think this is a quite nice one (in general TMS Component Pack is a great product including very nice components, congratulations!).
But there is a small design issue. I attached a picture of it, see the green button on upper left side. Most design buttons in Component Pack have the same issue. Tested on Android (LG G3 and Samsung Galaxy S4):
The same happens with TRectangle with XRadius / YRadius.